1. Field of the Invention
The present invention relates to a solid electrolytic capacitor, particularly a solid electrolytic multilayer capacitor, using an organic material such as an electrically conducting polymer, or an inorganic material such as a metal oxide, as the solid electrolyte. The present invention further provides a monolayer capacitor element for manufacturing a solid electrolytic multilayer capacitor.
2. Description of Related Art
In the manufacture of a solid electrolytic multilayer capacitor comprising the stacked monolayer of capacitor element using a conductive polymer (also called an electrically conducting polymer) or and the like, as the solid electrolyte therein, when the plural monolayer capacitor elements are stacked such that respective cathode areas are laid one on another to run parallel with each other, the anode areas must be bent so as to allow spot welding because each cathode area formed by providing a solid electrolyte layer and an electrically conducting layer in sequence has a thickness larger than that of the anode area. Due to this, stress concentrates in the vicinity of the boundary between the anode area and the cathode area of the monolayer capacitor element, and as a result, the capacitor performance deteriorates. Various attempts have been made to overcome this problem.
For example, in order to eliminate this difference between the thickness of the cathode area and the anode area, a method of inserting a metal sheet having a thickness corresponding to the space between respective anode areas of the plurality of monolayer capacitor elements during stacking of the monolayer capacitor elements (see, Japanese Unexamined Patent Application, No. Hei 5-205984), a method of forming an insulating resin layer in the space between respective anode areas and connecting those anode areas through a fine metal line or and the like, (see, Japanese Unexamined Patent Application, No. Hei 6-29163, and Japanese Unexamined Patent Application, No. Hei 6-84716) and a method of dividing a lead frame into pieces corresponding to respective anode area sites are known (see, Japanese Unexamined Patent Application No. Hei 4-167417).